Model organisms such as the fruit fly D. melanogaster provide powerful systems for the study of gene function and disease mechanisms. In spite of the many powerful genetic tools available for the Drosophila system, there is not yet a well-established method to generate mutant strains directly from DNA sequence data. This limitation is a particularly relevant issue at this time, with the recent release of the Drosophila genome sequence. The development of an appropriate technology would be of great use to the community of geneticists, molecular biologists, and biomedical researchers. The applicant's laboratory has identified a practical and efficient method, such that newly generated mutations in any genomic DNA of interest can be detected directly as nucleotide substitutions or as small deletions or insertions. They have demonstrated that it is possible to conduct a de novo chemical mutagenesis, and to directly assay DNA fragments generated from mutagenized chromosomes through use of DHPLC. The rate of mutation recovery obtained in their original study indicates a high degree of promise for this technique. Funds are requested to further develop and optimize the methodology, with the ultimate goal of making the technique available to the research community. There are a number of advantages that this novel technology will offer over current methods for the study of gene function. It will allow the direct recovery of mutations in genes or sequences for which there are no mutations currently available. It will allow the recovery of a whole allelic series of mutations in a given gene, including recessive, dominant and conditional mutations. It will also allow the recovery of mutations without any selection based upon phenotype. Finally, this technology should ultimately be applicable to other model genetic organisms as well as to Drosophila.